Fortification Levels Research Articles

Easy fabrication of aminated graphene oxide functionalized magnetic nanocomposite for efficient preconcentration of phenolic acids prior to HPLC determination: Application in tea-derived wines

In this study, aminated graphene oxide functionalized magnetic nanocomposite (AGMN) was facilely synthesized by one-pot hydrothermal approach and acted as the extraction phase of magnetic solid phase extraction (MSPE) of phenolic acids (PAs). Characterization results revealed that the AGMN possessed satisfying saturation magnetism and abundant functional groups. Under the optimal extraction parameters, the proposed AGMN/MSPE presented high enrichment capability to PAs. Sensitive and dependable method for measurement of PAs in wine was proposed by the combination of AGMN/MSPE and HPLC/DAD. Limits of detection and limits of quantification were in the ranges of 0.031–0.23 μg/L and 0.10–0.78 μg/L, respectively, and the RSDs for approach precision varied from 1.8% to 8.9%. Recoveries at low, medium and high fortified levels varied from 84.6% to 116%. The suggested method was used to quantify investigated PAs in ten kinds of Tieguanyin tea-derived wines, and found the contents of PAs in wines were related to the quality of tea-leaves and alcohol content.

Determination of organophosphorus and synthetic pyrethroid pesticide residues and their variability in large size fruit crops

Variability of pesticide residues in food item plays a key role for the evaluation of consumer food safety. However, variability factors (VFs) derived from the large size fruit crops are still scarce. Therefore, the present work was aimed to quantify pesticide residues and to estimate VFs in large size fruit crops of mango and guava. A total of 140 mango and 130 guava samples from different marketplaces in Bangladesh were collected to estimate the variability of pesticide residues (acephate, diazinon, malathion, fenitrothion, chlorpyrifos, quinalphos, dimethoate and cypermethrin) by in-house validated methods based on modified QuEChERS extraction and gas chromatography coupled with electron capture detector (ECD) and flame thermionic detector (FTD). The method was validated at three fortification levels (0.01, 0.10 and 0.30 mg kg-1 ) and satisfactory recoveries (80-111%) with relative standard deviation (RSDr ) ≤ 13% were achieved. A wide variation of residues was found in the analyzed samples. In the case of mango, the ranges of residues were 0.011-0.314, 0.015-0.04, and 0.05-0.291 mg kg-1 , respectively, for cypermethrin, chlorpyrifos, and dimethoate, while in the case of guava, the ranges were 0.04-0.113, and 0.03-0.290 mg kg-1 , respectively, for cypermethrin and acephate. The average VF for mango was 4.06 and it was 5.70 for guava. VFs originating from the marketed samples of mango and guava are reported in this study for the first time. The estimated VFs were higher than the default value of 3, therefore, the default VFs should be reconsidered when more data are obtained regarding large size crops. © 2021 Society of Chemical Industry.

Edible mushrooms dietary fibre and antioxidants: Effects on glycaemic load manipulation and their correlations pre-and post-simulated in vitro digestion

In this study, mushroom stems were separated from the fruiting body of two edible mushrooms, white button mushroom (WB, Agaricus bisporus) and oyster mushroom (OY, Pleurotus ostreatus), and their functionalities were compared in wheat flour noodles at fortification levels of 5, 10, 15%. The inclusion of WB led to higher protein content than OY, which had more dietary fibre, especially insoluble dietary fibre. The fortification of mushrooms decreased the area under the curve (AUC) of reducing sugars released during in vitro digestion significantly (p < 0.05). WB fortified noodles yielded higher antioxidant capacities than OY fortification, whereas the digesta following digestion of WB and OY groups shared similar free accessible weighted average antioxidants. Mushrooms derived insoluble dietary fibre was negatively correlated with AUC and positively correlated with antioxidants (p < 0.05), suggesting the efficacy of mushroom stems over post-prandial glucose release of foods and providing the antioxidant environment to the intestine.

Combined d-SPE-QuECHERS-Cold Bath Extraction and GC/MS for the Determination of 24 Polycyclic Aromatic Hydrocarbons in Stranded Green Sea Turtles, Chelonia Mydas (Linnaeus, 1758)

Priority pollutants polycyclic aromatic hydrocarbons (PAHs) in muscle and livers of stranded green sea turtles, Chelonia mydas (Linnaeus, 1778) were extracted using a quick, easy, cheap, effective, rugged and safe method followed by Gas chromatography/mass spectrometry (GC/MS). Changes to the nature of the extracting solvents, the reaction conditions and the number of co-extractives in the extraction procedure was established to account for the variability of the tissue samples’ matrix effect and condition code of each turtle examined. The analytical performance was assessed taking into consideration the analytical recoveries at different fortification levels, matrix effect and instrumental parameters such as selectivity, linearity, and the limits of detection and quantification. Recoveries between 72 and 162% were obtained for most PAHs in liver and 24-107% in muscle samples. Matrix effects assessments showed medium matrix effect, while LOD was on average 0.04 µg g−1 and LOQ was on average 0.13 µg g−1. The extraction showed the best recoveries when extracted using acetonitrile at cold temperature conditions of around 4 °C. Validation results through PCA and correlation analyses showed the suitability of this method for simultaneous determination and confirmation of PAHs in both liver and muscle of stranded turtles at different decomposition levels, matrix complexities and specimen sizes.

Effect of Calcium Fortified Foods on Health Outcomes: A Systematic Review and Meta-Analysis.

Calcium supplementation and fortification are strategies widely used to prevent adverse outcome in population with low-calcium intake which is highly frequent in low-income settings. We aimed to determine the effectiveness and cost-effectiveness of calcium fortified foods on calcium intake and related health, or economic outcomes. We performed a systematic review and meta-analysis involving participants of any age or gender, drawn from the general population. We searched PubMed, Agricola, EMBASE, CINAHL, Global Health, EconLit, the FAO website and Google until June 2019, without language restrictions. Pair of reviewers independently selected, extracted data and assessed the risk of bias of included studies using Covidence software. Disagreements were resolved by consensus. We performed meta-analyses using RevMan 5.4 and subgroup analyses by study design, age group, and fortification levels. We included 20 studies of which 15 were randomized controlled trials (RCTs), three were non-randomised studies and two were economic evaluations. Most RCTs had high risk of bias on randomization or blinding. Most represented groups were women and children from 1 to 72 months, most common intervention vehicles were milk and bakery products with a fortification levels between 96 and 1200 mg per 100 g of food. Calcium intake increased in the intervention groups between 460 mg (children) and 1200 mg (postmenopausal women). Most marked effects were seen in children. Compared to controls, height increased 0.83 cm (95% CI 0.00; 1.65), plasma parathyroid hormone decreased −1.51 pmol/L, (−2.37; −0.65), urine:calcium creatinine ratio decreased −0.05, (−0.07; −0.03), femoral neck and hip bone mineral density increased 0.02 g/cm2 (0.01; 0.04) and 0.03 g/cm2 (0.00; 0.06), respectively. The largest cost savings (43%) reported from calcium fortification programs came from prevented hip fractures in older women from Germany. Our study highlights that calcium fortification leads to a higher calcium intake, small benefits in children’s height and bone health and also important evidence gaps for other outcomes and populations that could be solved with high quality experimental or quasi-experimental studies in relevant groups, especially as some evidence of calcium supplementation show controversial results on the bone health benefit on older adults.

Development and Validation of an Analytical Method for the Quantification of Arabinose, Galactose, Glucose, Sucrose, Fructose, and Maltose in Fruits, Vegetables, and Their Products

The paper presents a method for the simultaneous determination of arabinose, galactose, glucose, sucrose, fructose, and maltose in fruits, vegetables, and their products using ion chromatography-pulsed amperometric detection on a gold working electrode. Sample preparation involved simple extraction, dilution with water, and filtration before injection into the system. Separation of the analytes was performed with gradient elution on a Thermo Scientific CarboPac PA20 Analytical Column (3.0 × 150 mm) and a Guard column (2 mm × 50 mm) with a mobile phase. The optimized parameters were an eluent concentration of 10 mmol/L, a column temperature of 30 °C, and a flow rate of 0.4 mL/min. In methodological evaluation, parameters (selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), relative standard deviation (RSD), recovery percentages, and CV%) resulted in compliance with reference values at each level of fortification. All validation parameters were acceptable in the characterization of sugars in fruits, vegetables, and their products. After method validation, we analyzed the sugar content in fresh and dried jujube. The method was accurate, reliable, and reproducible and can be used for the determination of arabinose, galactose, glucose, sucrose, fructose and maltose in fruits, vegetables, and their products.

Optimization of a QuEChERS Based Analytical method for the Determination of Organophosphorus and Synthetic Pyrethroid Pesticide Residues in Betel Leaf

ABSTRACT A novel method has been developed and validated for the first time in order to determine eight pesticide residues (acephate, diazinon, malathion, fenitrothion, chlorpyrifos, quinalphos, dimethoate and cypermethrin) in betel leaf using quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction in combination to Gas Chromatography (GC) coupled with Flame Thermionic Detector (FTD) and Electron Capture Detector (ECD). In this study, the optimisation of cleanup materials was done properly and found that 600 mg anhydrous MgSO4, 150 mg activated charcoal powder, and 120 mg PSA (Primary Secondary Amine) was the best combination for proper cleanup of betel leaf matrix. Recoveries for all the selected pesticides at fortification levels of 0.02, 0.1, and 0.3 mg/kg ranged from 86% to 108% with RSDr ≤ 9% and the matrix matched calibration curve showed good linearity (r2 ≥ 0.996). The limit of detection ranged from 0.003 to 0.005 mg/kg and the limit of quantification was 0.02 mg/kg, which was lower than the EU-MRLs. The matrix effects of the selected pesticides were also evaluated in this study and found that cypermethrin had a prominent matrix effect (+124%). The proposed method was applied successfully to analyse 110 fresh betel leaf samples and found that 12 were contaminated with cypermethrin, chlorpyrifos, and dimethoate at a level above EU-MRLs. The consumers are at high health risk as the detected levels of cypermethrin and chlorpyrifos residues were up to 78 and 39 times higher than the EU-MRLs, respectively, and the estimated highest Health Risk Index (HRI) was 5.40.

Multiresidue Analytical Method for Pesticides in Soybean Extract.

Developed and validated a fast, simple and effective method based on the use of DLLME technique and determination by GC-MS of 26 pesticides in SE. To carry out the extraction of the pesticides of the matrix, 70μL of mix of pesticides (1.5μg/mL) was added to 5.0mL of SE, containing 1.0g of sodium chloride and 3.0mL of acetonitrile. The results of validation were suitable. The calibration curve was linear in the range of 0.500-5.0μg/mL. The method showed a limit of detection and quantification of 0.17μg/mL and 0.50μg/mL, respectively. The recovery recovering between 47% and 115%, with relative standard deviation (RSD) of <20% for fortification levels (range of 1.0-3.0μg/mL). The method validated can be applied for routine analysis in soy-based drinks, considering it is fast, easy to perform and has satisfactory validation results.

In vitro Degradation of S-Metolachlor in Different Types of Soils

In vitro dissipation of S-metolachlor (87.2 EC) is reported in sandy, sandy loam, medium black calcareous and heavy black soils at 0.4 – 0.8 μg g−1 (T1) and 0.8 -1.2 μg g−1 (T2) levels of fortification. S-metolachlor showed biphasic mode of dissipation in the four types of soil with half-life ranging from 1.0 to 17.7 d and 4.6 – 43.0 d for phase-I and phase-II, respectively. The rate of dissipation was found slightly faster in sandy and sandy loam soils compared to medium black calcarious and heavy black soils (sandy> sandy loam >medium black calcareous> heavy black).

Effect of pH on Persistence and Degradation of Cyantraniliprole in Aqueous Media

The persistence and degradation of cyantraniliprole in water has been reported at six different pH values viz. 2, 4, 6, 7, 9.2 and 10. Water samples of different pH were fortified with standard solution of cyantraniliprole at 10 mgL−1 and kept at 25±2°C. Cyantraniliprole and its two metabolites IN-J9Z38 and IN-JCZ38 were monitored using HPLC-PDA. Calibration curves in the concentration range 0.001–10 mgL−1 were found to be linear for all the three analytes with coefficient of determination R2> 0.991. Recoveries of cyantraniliprole, IN-J9Z38 and IN-JCZ38 from water at 0.05, 0.01 and 0.005 mgL−1 fortification levels were in the range of 89.79–93.66 per cent with relative standard deviation of 2.19–5.16 per cent Limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.001 and 0.005 mgL−1 at 3:1 and 10:1 signal to noise ratio, respectively. Half-life of cyantraniliprole in different pH solutions ranged from 2.8 to 99.0 d. Cyantraniliprole was found to be highly persistent in acidic solutions (pH 2 and 4). In alkaline solutions (pH 9.2 and 10), it degraded very fast with the formation of IN-J9Z38 as its major metabolite.

Nutritional attributes of wheat bread fortified with convectively dried chokeberry powder

Chokeberry (Aronia melanocarpa L.) has a positive effect on human health, and therefore it can be used as a beneficial component for food (e.g. wheat bread) fortification. Dried chokeberry powder (CP), obtained by convective drying at 50, 60, and 70°C, fortified bread samples by replacing wheat flour at levels of 1, 2.5, 5 and 10%. Bread samples fortified with chokeberry were characterized by a decrease in total starch and protein contents and an increase in total sugar, mineral (Mg, Ca, Cu), and fat components; unsaturated oleic acid was reduced, unlike unsaturated linoleic and linolenic acids. All developed mathematical models for starch, protein, fat, and minerals in bread supplemented with CP were characterized by statistically insignificant residual variances and high values of R2. Z-score analysis showed the optimal segment and total scores of bread fortified with CP. Chokeberries dried at a temperature of 60°C showed the best nutritional attributes. Wheat bread enriched with CP in the amount of 10% had the highest level of fortification.

Effects of Plant Ash Fortification on &amp;lt;i&amp;gt;okpa&amp;lt;/i&amp;gt; the Ethnic and Traditional Snack of Southeast Nigeria

<i>Okpa</i> is a popular traditional snack widely relished by both rich and poor including the elderly people of south eastern part of Nigeria and therefore could be a good vehicle for nutrient intervention programmes. It is rich in protein but not a good source of minerals which fortification with empty palm bunch ash will enhance to prevent osteoporosis and other related diseases among the elderly people. Bambara groundnut paste was prepared, mixed with water and seasonings, and divided into four batches. Three out of the four batches were fortified each with 1, 5 and 10% ash as samples B, C and D respectively. Each batch was separately wrapped (250 ml) in plantain leaves and steamed. The remaining unfortified batch served as control (sample A). Proximate and mineral contents were evaluated with standard analytical methods. Sensory evaluation was determined subjectively with 20 semi-trained panelists. With increase in ash fortification levels, there was increase in moisture (58.40-59.50%), fibre (1.20-1.30%), ash (1.35-1.55%), calcium (72.50-85.38 mg/100g), magnesium (114.45-126.46 mg/100g), zinc (5.70-6.33 mg/100g), iron (1.45-2.36 mg/100g), phosphorous (206.32-219.40 mg/100g) and sodium (12.27-14.92 mg/100g). Only protein (8.63-8.43%), fat (4.15-4.00%), carbohydrate (25.83-25.23%), energy (164.63-160.31 Kcal), and acceptability (7.05-4.10) decreased. The control sample had the highest acceptability score which was not statistically different from samples with 1 and 5% ash. Ash concentrations of 1 and 5% enhanced the taste, appearance, aroma and texture of the <i>okpa</i> more than the control. There was significant increase in most nutrients most especially the minerals more than the control.

Iodine Content of Processed Foods and Condiments Sampled in China, 2017-2019

Introduction: Facing the challenge of increasing consumption of processed foods in China, along with the demand for salt reduction, and dynamic adjustment of universal salt iodization (USI) policy, it is necessary to timely evaluate the distribution of iodine content in processed foods and condiments, so as to provide more accurate data for population dietary iodine intake assessment. Methods: From markets in 6 cities and e-commerce platforms, cereal, tuber, legume, meat, fish, egg, and dairy products, and condiments, consumed by volunteers who attended in iodine intake investigation, and top selling products in particular with well-noted brands were preferentially sampled during 2017 to 2019. After being mixed and homogenized, each sample was detected by ICP-MS method. The range and medium of iodine content in each type of product were given. Results: After merging samples with close value in the same style of the same brand, and screening out samples with no added salt or low sodium content (≤120 mg/100g), total 725 data were sub-grouped and analyzed. In comparison with the 95th percentile of the iodine distribution in relative nature source, assessed by our previous study, nearly 77% of products made from grains, potatoes, beans, nuts, livestock and poultry meat were presumed to be processed with iodized salt. In somewhat, related with sodium value marked on food labeling, the median iodine ranged from 1.1 mg/100g to 149 mg/100g. The variation of iodine in egg, milk and fish made products, and seaweed or with seaweed products was greatly affected by the background of ingredients, the median content most floated between 12.8 mg/100g and 86.8 mg/100g, even up to 1800 mg/100g in seasoned seaweed. Based on the frequency of iodine digital and the ratio of iodine to sodium, it was speculated that nearly 90% of soy sauce and 73.5% of other seasonings like vinegar, sauce, paste, etc., were not added iodized salt, with overall median iodine 4.0 mg/100g and 12 mg/100g respectively. Conclusion: Using iodized salt in processed foods is an approach of USI police. Affected by the nature backgrounds of ingredients composed, the amount of salt used, and the regulated fortification level, iodine content in each kind of product varied largely. It’s important to establish a monitoring system in processed foods, as well as fortification salt, to control the benefit and risk of iodine health.

Determination of Organochlorine and Synthetic Pyrethroid Pesticide Residues in Water Samples Collected from Different Locations of Bangladesh

The present study was aimed to validate an analytical method for the quantification of 19 organochlorine and 2 synthetic pyrethroid pesticide residues in water samples using modified quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction and Gas Chromatography coupled with Electron Capture Detector (ECD). The selected pesticide residues were determined by in-house validated method. The analytical method was validated by evaluating the accuracy, precision, linearity, limit of detection (LOD) and limit of quantification (LOQ). The average recoveries of the selected pesticides ranged from 78% to 117% with RSDr ≤ 12% in two fortification levels of 0.02 and 0.1 mg/L. The linearity was ≥0.995 for all of the selected pesticides. The LOD ranged from 0.003 to 0.006 mg/L and the LOQ was 0.02 mg/L for all the selected analytes. This method was applied satisfactorily for the residue analysis of 108 water samples collected from nine districts of Bangladesh. Among the analyzed samples, only 4 had cypermethrin residues (0.026 mg/L, 0.034 mg/L, 0.045 mg/L and 0.05 mg/L). The level of detected cypermethrin residues were above the WHO recommended guide line values of water quality.

Study on Seismic Response and Damping Measures of Surrounding Rock and Secondary Lining of Deep Tunnel

Tunnel construction is gradually developing to areas with high in situ stress; the deeper the tunnel construction, the more intense the earthquake disturbance. Under the background of frequent earthquakes, the seismic characteristics of tunnels become an important content related to the safety and stability of engineering structures. In view of the key problems of seismic response and vibration reduction measures for complex deep buried tunnels, the methods of advanced grouting and foam concrete aseismic are studied in this paper. Firstly, through geological survey, the in situ stress and geological conditions of the study area are analyzed. The structural characteristics of surrounding rock and related rock mechanics parameters are analyzed. The failure criterion of concrete lining under dynamic load is studied theoretically, and the relevant numerical calculation parameters are modified. A numerical model based on viscous boundary conditions is established. Through numerical calculation, the seismic response of tunnel surrounding rock and lining under different damping measures is analyzed. The research results have theoretical research value and social and economic benefits for ensuring the safety and stability of tunnel structure and improving the seismic fortification level.

Determination of trace residues level of pesticides in some vegetables growing in Algeria by GC/µECD and GC/MS

An analytical multiresidue method for the simultaneous determination of various classes of pesticides in vegetables (tomato, pepper, hot pepper and potato) was developed. Vegetable samples are extracted with acetonitrile.&#x0D; Final determination was made by gas chromatography with µ-Electron Capture Detection(µ-ECD) for organochloride pesticides. Organophosphorus, pyrithrinoids and other pesticides analysis was carried out by gas chromatography coupled with mass spectrometry in the selected ion monitoring (SIM) mode. The identification of compounds was based on retention time and on comparison of the primary and secondary ions. Recovery studies were performed at various fortification levels of each compound and the recoveries obtained ranged from 70% to 127 % with relative standard deviations lower than 8%. The method showed good linearity over the range studied and the detection and quantification limits for the pesticides studied varied from 0.015 to 0.030 µg.g-1and 0.05 to 0.1 µg.g-1, respectively. The proposed method was used to determine pesticides levels in peppers, hot pepper and tomatoes grown in multichapelle greenhouses at Biskra region and potato grown at Setif region in Algeria.

Development of functional whey cheese enriched in vitamin D3: nutritional composition, fortification, analysis, and stability study during cheese processing and storage

“Ricotta” cheese is a traditional and popular Italian fresh whey cheese commonly produced from cow’s milk. Food fortification is an efficient strategy to reduce the high global prevalence of vitamin D deficiency. This study aims to study the chemical-nutritional analysis of ricotta cheese and to assess its suitability as a dairy matrix for vitamin D fortification. The chemical-nutritional analyses revealed that ricotta cheese is a good source of proteins (7.8 g/100 g) with high levels of branched-chain amino acids (1.8 g/100 g). Moreover, ricotta contains high levels of calcium (0.4 g/100 g) and phosphorus (0.2 g/100 g). 50 mg of vitamin D3 were added to 95 kg of cheese reaching a mean fortification level of 41.4 ± 4.0 µg/100 g of ricotta cheese. The fortification study showed that vitamin D homogenously distributes in ricotta cheese after the homogenisation process. Moreover, vitamin D3 has high heat stability (93.8 ± 1.8%) and remains stable throughout the shelf-life of the fortified food. This study demonstrates that ricotta cheese represents an ideal alternative dairy matrix for vitamin D3 fortification.

Grape Pomace Valorization: A Systematic Review and Meta-Analysis.

This systematic review aimed to collect data and analyze the possible use of grape pomace, a winemaking industry byproduct, in the production of fortified foods. The English articles found in Web of Science, Scopus, and Google Scholar, from January 2006 until May 2020, were used for the conduction of overview tables and meta-analysis. The systematic review emphasized the two main issues concerning grape pomace application to other food products: (i) grape pomace contains high amounts of health promoting compounds; and (ii) the use of grape pomace is influencing the waste management. The grape pomace has been used in the fortification of plant origin food, meat, fish, and dairy products, mainly due to higher polyphenols and dietary fiber contents. The fortification was declared as successful in all studied food types. The change of color, caused by polyphenolic compounds, was mainly observed as an adverse effect of the fortification. Higher levels of fortification also caused notable undesirable changes in texture. The most valuable influence of the grape pomace addition according to included papers and meta-analysis is certainly a higher nutritional quality and oxidative stability of fortified products, reflected as higher polyphenol and total dietary fiber content.

An optimized LC–MS/MS workflow for evaluating storage stability of fluroxypyr and halosulfuron-methyl in maize samples

Pesticide registration ensures the safety of agricultural products; however, the backlog of field samples often requires lengthy storage periods. Thus, the stability of pesticide residues in stored samples is required information for pesticide registration. We monitored the degradation rates of fluroxypyr and halosulfuron-methyl in maize straw, mature maize grain, and fresh corn matrices to evaluate their storage stability. Analytes were extracted and cleaned up with a modified Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method and then detected with liquid chromatography tandem-mass spectrometry. We optimized the workflow by testing different clean-up sorbents, LC columns, and chromatographic methods. The linearity correlation coefficients of fluroxypyr and halosulfuron-methyl in the three matrices were ≥0.994. At three fortification levels, the mean recoveries of fluroxypyr and halosulfuron-methyl were 84.2–114.8% and 83.8–105.5% with relative standard deviations of 2.4–9.4% and 2.7–10.2%, respectively. Degradation of the two herbicides in the three matrices was less than 30% over the 70-day storage period, indicating fluroxypyr and halosulfuron-methyl are stable in the tested maize matrices when stored at −20 °C for at least 70 days. This study provides a reference method for pesticide residue analysis and can be used as a guide to develop accurate and reasonable pesticide registration procedures.

In vitro dissipation of S-metolachlor herbicide in different pH water

In vitro dissipation of S-metolachlor was studied in neutral, acidic and basic water at 0.2 – 0.4 µg/g (T1) and 0.4 - 0.8 µg/g (T2) levels of fortification at All India Network Project on Pesticide Residues, ICAR, Unit-9, Anand Agricultural University, Anand (Gujarat), India. The S-metolachlor dissipated much rapidly in acidic and basic water as compared to neutral. Between the acidic and basic water, the rate of degradation was comparatively faster in basic water. In all the three pH water, the degradation followed first order kinetic with mono and biphasic mode. The herbicide underwent degradation at much faster rate in acidic and basic waters as the residue reached below determination level (BDL) of 0.05 µg mL-1 with half-life values ranging from 1.8 to 12.5 day and 12.04 to 301.0 day for Phase-I and Phase-II, respectively. However, in neutral water the rate of degradation was much slower and the residues reached below determination level on the 60th day with half-life ranging 3.4 to 12.5 and 100.3 to 300.1 days for Phase-I and Phase-II, respectively.